backend: Replace linkedlist with map for counter diagnostics

Author: pimpalemahesh

src/tracing/esp32_diagnostic_trace/Counter.cpp

@@ -23,43 +23,29 @@ namespace chip {
 namespace Tracing {
 namespace Diagnostics {
 
-// This is a one time allocation for counters. It is not supposed to be freed.
-ESPDiagnosticCounter * ESPDiagnosticCounter::mHead = nullptr;
+std::map<const char *, uint32_t> ESPDiagnosticCounter::mCounterList;
 
-ESPDiagnosticCounter * ESPDiagnosticCounter::GetInstance(const char * label)
+void ESPDiagnosticCounter::CountInit(const char * label)
 {
-    ESPDiagnosticCounter * current = mHead;
-
-    while (current != nullptr)
+    if (mCounterList.find(label) != mCounterList.end())
     {
-        if (strcmp(current->label, label) == 0)
-        {
-            current->instanceCount++;
-            return current;
-        }
-        current = current->mNext;
+        mCounterList[label]++;
+    }
+    else
+    {
+        mCounterList[label] = 1;
     }
-
-    // Allocate a new instance if counter is not present in the list.
-    void * ptr = Platform::MemoryAlloc(sizeof(ESPDiagnosticCounter));
-    VerifyOrDie(ptr != nullptr);
-
-    ESPDiagnosticCounter * newInstance = new (ptr) ESPDiagnosticCounter(label);
-    newInstance->mNext                 = mHead;
-    mHead                              = newInstance;
-
-    return newInstance;
 }
 
-int32_t ESPDiagnosticCounter::GetInstanceCount() const
+int32_t ESPDiagnosticCounter::GetInstanceCount(const char * label) const
 {
-    return instanceCount;
+    return mCounterList[label];
 }
 
-void ESPDiagnosticCounter::ReportMetrics()
+void ESPDiagnosticCounter::ReportMetrics(const char * label)
 {
     CHIP_ERROR err = CHIP_NO_ERROR;
-    Counter counter(label, instanceCount, esp_log_timestamp());
+    Counter counter(label, GetInstanceCount(label), esp_log_timestamp());
     DiagnosticStorageImpl & diagnosticStorage = DiagnosticStorageImpl::GetInstance();
     err                                       = diagnosticStorage.Store(counter);
     VerifyOrReturn(err == CHIP_NO_ERROR, ChipLogError(DeviceLayer, "Failed to store Counter diagnostic data"));

src/tracing/esp32_diagnostic_trace/Counter.h

@@ -23,6 +23,7 @@
 #include <esp_log.h>
 #include <lib/support/CHIPMem.h>
 #include <lib/support/CHIPMemString.h>
+#include <map>
 #include <string.h>
 
 namespace chip {
@@ -39,20 +40,23 @@ namespace Diagnostics {
 
 class ESPDiagnosticCounter
 {
-private:
-    static ESPDiagnosticCounter * mHead; // head of the counter list
-    const char * label;                  // unique key ,it is used as a static string.
-    int32_t instanceCount;
-    ESPDiagnosticCounter * mNext; // pointer to point to the next entry in the list
+public:
+    static ESPDiagnosticCounter & GetInstance(const char * label)
+    {
+        static ESPDiagnosticCounter instance;
+        CountInit(label);
+        return instance;
+    }
 
-    ESPDiagnosticCounter(const char * labelParam) : label(labelParam), instanceCount(1), mNext(nullptr) {}
+    int32_t GetInstanceCount(const char * label) const;
 
-public:
-    static ESPDiagnosticCounter * GetInstance(const char * label);
+    void ReportMetrics(const char * label);
 
-    int32_t GetInstanceCount() const;
+private:
+    ESPDiagnosticCounter() {}
 
-    void ReportMetrics();
+    static std::map<const char *, uint32_t> mCounterList;
+    static void CountInit(const char * label);
 };
 
 } // namespace Diagnostics

src/tracing/esp32_diagnostic_trace/DiagnosticTracing.cpp

@@ -146,7 +146,7 @@ void ESP32Diagnostics::LogMetricEvent(const MetricEvent & event)
 
 void ESP32Diagnostics::TraceCounter(const char * label)
 {
-    ESPDiagnosticCounter::GetInstance(label)->ReportMetrics();
+    ESPDiagnosticCounter::GetInstance(label).ReportMetrics(label);
 }
 
 void ESP32Diagnostics::TraceBegin(const char * label, const char * group)